Cancelation of Netstar contract

I cancelled my contract beginning of May 2022. End of May i paid the settlement amount and sent proof of payment. No feedback received after that. Phoned them second week in June and requested tracking unit to be removed. They asked for proof of payment to be sent again, which I did. Once again no feedback. Is there any one competent at Netstar that can contact me and make arrangements to have your travking device removed